UI layout: enable collapsing index bar on left for improved use of screen space

[ahelwer]

I like to use a vertical monitor off to the side for reading documentation as I work. On the Alloy page, the left index bar takes up a large amount of screen space:

It would be nice if the index bar could be collapsed, similar to in the Python docs: https://python.readthedocs.io/en/latest/index.html

[ahelwer]

Although I do see that this is part of a theme that is used elsewhere, for example https://docs.readthedocs.io/en/stable/intro/getting-started-with-sphinx.html#quick-start so maybe I should open this request against the theme itself

[ahelwer]

I see this issue has already been opened against the theme itself: https://github.com/readthedocs/sphinx_rtd_theme/issues/987

[hwayne]

I could probably whip up a css to do this, ugh css